Silicones (more accurately called polymerized siloxanes or polysiloxanes) are mixed inorganic-organic polymers with the chemical formula [R2SiO]n, where R=organic groups such as methyl, ethyl, and phenyl. These materials consist of an inorganic silicon-oxygen backbone ( . . . —Si—O—Si—O—Si—O— . . . ) with organic side groups attached to the silicon atoms, which are four-coordinate. In some cases organic side groups can be used to link two or more of these —Si—O— backbones together. By varying the —Si—O— chain lengths, side groups, and crosslinking, silicones can be synthesized with a wide variety of properties and compositions. They can vary in consistency from liquid to gel to rubber to hard plastic. The most common siloxane is linear polydimethylsiloxane, a silicone oil.
Polysiloxane emulsions are well known in the art and may be categorized by the size of the polysiloxane particles and the appearance of the emulsion. Typically three categories of silicone emulsions are recognized in the art-standard emulsions, fine emulsions and microemulsions. The term emulsion used here in encompasses the three individual types of silicone emulsions.
Silicone standard emulsions are characterized by a large particle size (typically greater than 300 nanometers) and appear to the human eye to be opaque (impenetrable to light). Silicone standard emulsions are most commonly identified as those having an intense white appearance. Silicone fine emulsions are characterized by a smaller particle size, from 300 to 140 nanometers, and are identified as those compositions which visually may be slightly opaque to very slightly translucent (transmitting light but with distortions). Silicone microemulsions are characterized as those having a particle size of less than 140 nanometers and visually appear translucent to transparent (transmitting light without distortion).
Out of the three types of silicone emulsions, fine emulsions and microemulsions are generally the most desired due to their smaller particle size and higher stability. Microemulsions are often desired due to their translucent to transparent appearance.
Compositions containing a polyorganosiloxane are well known in the art. For example, liquid waterproofing agents based on polyorganosilxonaes have been developed for use in treating porous, lightweight, fibrous ceramic thermal-insulation materials in both tile (rigid) and blanket (flexible) forms. Whereas silane-based waterproofing materials developed previously for this purpose are toxic and volatile and must be applied in tedious procedures (involving repeated injection at multiple locations by use of syringes), the present formulations are nontoxic and nonvolatile and can be applied by ordinary coating procedures.
Emulsions of polyorganosiloxanes (sometimes referred to as silicones) have been known in the art for many years. Examples of such prior art are:                Hyde & Wehrly U.S. Pat. No. 2,891,920;        Findlay & Weyenberg U.S. Pat. No. 3,294,725;        Johnson, Sam & Schmidt U.S. Pat. No. 4,221,688;        Kevita U.S. Pat. No. 4,502,889;        Traver, Thimneur & Zotto U.S. Pat. No. 4,600,436;        Kalinowski, Liles & Shephard U.S. Pat. No. 5,145,907;        Berg & Joffre U.S. Pat. No. 5,674,937; and        Gee U.S. Pat. No. 6,316,541.        
However, there is a need in the industry for new and improved silicones, that is, polyorganosiloxane-containing compositions.
Specifically, there is a need in the industry for new and improved emulsions of polyorganosiloxanes that carry a cationic surface charge and deliver an elastomeric treatment (such as a film) to various surfaces and substrates, such as hair, skin, wood, rubber, synthetic organic polymers, metals, ceramics, fiberglass, flat glass, textiles, etc.